Problem: Michael ate 3 slices of pie. Omar ate 5 slices. If Michael ate $\dfrac{3}{9}$ of the pie, what fraction of the pie was eaten?
If 3 slices represent $\dfrac{3}{9}$ of the pie, there must have been a total of 9 slices. $\text{fraction of pie eaten} = \dfrac{\text{number of slices eaten}}{\text{number of slices total}}$ They ate ${8}$ out of $9$ slices. They ate $\dfrac{8}{9}$ of the pie.